R,G,B = map(int,raw_input().split())
M = min(R,G,B)
R,B = sorted([R-M,G-M,B-M],reverse = True)[:2]
ans = M
while 1:
    if R >= B > 0 and R >= 3:
        R -= 3
        B -= 1
        ans += 1
    elif B >= R > 0 and B >= 3:
        R -= 1
        B -= 3
        ans += 1
    else:
        break
print ans